Project Korg Polysix (New battery)

The first part of this operation succeeded.  I actually only made one little mistake wich was easily fixed. As you can see in the image below that hateful leaking battery is replaced with a CR2032 Lithium Battery that is placed in a socket. I actually had to put the battery upside down in the socket since the socket itself could not fit with +/- in the right direction. Thats really a shame but I promised myself to mark the socket in some way before I close this project.

IMG_7208

To the left of the battery there is now an empty socket where the damaged 74LS08 used to sit. To the left of that socket there is another new 74LS08 seated in its socket. I changed both of them when I was at it. Actually you can see the only mistake I made in this picture. Yes I forgot to put one of the 74LS08 chips back. When I switched the Polysix back on 4 of the 8 Program switches was lit. When that chip was put back in its socket everything started working. Finally to the right of the battery there used to be one capacitor (C40) that is now removed and just above that there used to be a resistor (R91) that resistor is replaced with a diode. The purpose of this diode is to protect the battery from voltage when the power is switched on. The new battery is not rechargeable so feeding it with power is a bad idea.

Once I had the Polysix up and running I downloaded the factory presets as wav-files and send the via my soundcard to the synth. I had to turn up the volume once but the Polysix updated the banks with the factory presets almost at once. Nice engineering with tolerance Korg!!! I never owned a working Korg Polysix so I had no idea what the presets sounded like. But now I know. They sound like shit! Well they are obviously from the eighties and my Korg Polysix still sounds very bad and noisey. But that´s what this project is supposed to fix in the end. Listen to this as I switch through the presets and in the end turn to a sawtooth and try out the filter and finally the chorus effects.

This Polysix sounds kind of weak to me. Some patches suddenly has some obscene clipping, perhaps they were in unison I didn´t check. And the noise level is terrible. Well there is plenty of work to do. Nothing that I do to the cpu-board will help with the bad sound but I am going to replace all the electrolytic capacitors and all of the 4000-series chips to expand the lifetime of this unit. I will report back as soon as the caps are exchanged. Soon enough I will try to get rid of the noise.

Share : twittergoogle plus
pinterest



Leave us a comment


Comments are closed.